Method of circulating air past the heating surfaces of warm-air furnaces for heating buildings which provides fresh air and ventilation



Dec. 11, 1928.

- F. H. WOOD METHOD OF CIRCULATING AIR PAST THE HEATING SURFACES OF WARMAIR FURNACES FOR HEATING BUILDINGS WHICH PROVIDES FRESH AIR ANDVENTILATION Filed Feb. 5, 1923 Patented Dec. 11, 1928. a

UNITEDIISTATESF FREDERICK H. woonor- CHICAGO, ILLINOIS, A'ssrcnon'IOILETTIEB. vwoon, or v v CHICAGO, ILLINOIS.

METHOD or CIRCULATING AIRIPASTFTHE HE T NG sunracns or AR -Amnes- NAcEsr03 HEATING, BUILDINGS WHICH rRovInEs FRESH AIR AND VENTILATION.

i Application filed February 5, 1923. semi aofeleeia This inventionrelates to improvements in the method of circulating airpast the heat.-ing surfaces ofawarm air furnace, whereby fresh exterior air may be usedin con unct1on with the recirculating air from the rooms, 1n such amanner, that these two currents of widely differing temperature maypass, .the heating surfaces of the furnace without exerting an adverseinfluence on each other that would tend to-retard their free passage tothe provides a means of ventllat-g rooms. It also ing the rooms.

It has been customary to mlngle the two currents, of fresh exterior airand the recirculating'air from the rooms, in one common hot-air chamber,or at, some polnt prior-to.

their passagepasttheheating surfaces, of the furnace. Finding that thismethod tends to retard the desired circulation of air,-I have devised amethod of passing thesetwocur rents past the heating surfaces in such aman ner that they are entirely separated-from each other. and not-mingle untll the fresh exterior air has been heated to a degree thatwill cause it to expand and rise in circulation.

A volume of'air must be withdrawn from the roomsto afford the entranceof an equah. volume of fresh exterior a1r,{and I accom-I invention, themethod of its operation is ilnature of which will be fully understoodfrom the description I give below when considered p to a ventilatingduct.

Figure 2 shows the elevation of the in similar relation. I

Figure 3 shows a modifiedformof the fresh exterior air compartment ofthe a heating lchimney flue N. lustrated in the accompanying drawing,the

erably from therooms of the building chamber designed-tomaintain theseparationv H PATENT men of thet-wo air currents duringtheir entirepassage through the furnace.

In Figures 1 and 2 A re resents tliecasing The or jacket ofthe furnace,the heater. air from therooms is returned to the furnace.

through the return duct C, entering within the jacket throughtheextension J of the returnduct. D-is the openingin the'jacket forpasses to this point, through a duct theexthe entrance of .the'freshexterior air which tremity of which is open to'the entranceof out ofdoor air. 7

F'and G are ly between the jacket and the heater.

more baflies which may be interposedwithin partitions extendingvertical- These partitions form a compartment withtheqacketin which the:fresh exterior air ,is warmed by contact with the heating surfaces ofthe heater B.. 1K representsone or '70 or to direct itscourseto.best'advantage' 'in warming the cold air, and may be used inf anyposition for that purpose, 1 v V In the drawing the outlet forthe heatedfreshair is shown at the top-of the'compartment but in practice it maybe desirable to I locate the outlet at some otherpart ofv thecompartment, the purpose ofthe comparte ,ment being to enable thewarming of the fresh air separately and before mingling itwith therecirculating am from the rooms.

L indicatesopenings in the jacket for warm air ducts leadingtothezrooms. ,Mis thesmoke pipe leadingfrom the heaterto the O is aVentilating duct extendingto the chimney flue and entering the flueat apoint well, below the point of entrance of the smoke;

pipe. P is a damper in the ventilating duct,

to regulate the volume of air passing through it, and may lee-arrangedto operate in unison V with .the vfront damper' afl'ording draft damperto the: fire, and when the draft is Iopen the damper in theventilatingiduct closes. furnace' Figure 3 is a modification ofjthefreshair compartment shown. in Figures 1 and2, in that its partitionsH and Iextend from the bottom to the top of, the-jacket; and have anPrefopening for a duct leading to the rooms, the fresh air passingthrough such a compartment being maintained separate from therecirculating air from the rooms in its passage through the furnace.

Having shown a means by which my method of circulating air through afurnace may be operated, I will proceedto describe the manner of itsoperation.

The fresh exterior air enters the compartment withinthe acket of thefurnace provided for it, and throughwhich it passes in direct contactwith the heating surfaces and. is (321-. panded and rises incirculation, having received a degree of heat quite equal to. that ofthe recirculating current from the. rooms at the point of its entranceto. within the.

jacket of the furnace. It may then be. min

gled with the recirculating air current withoutdisturbingthe,circulationof that current, or it maybe directed from. its compartment direct tothe rooms without mingling with. the recirculating current within. thejacket of thefurnace.

The tendency ofthe heated fresh airto circulate and pass to the rooms isaided by the draft of the chimney fiue which draws the vitiated air fromthe rooms through the ventilating duct'and into the chimney where itpasses upwardand out of doors. Naturally theair sowithdrawn. from therooms mustbe replaced by out of door air, andthe fresh air duct affordsa means of least resistance to such. incoming current.

It-is obvious. that the air could be withdrawn, from the rooms bymechanical means, but I prefer to. rely on the one at hand in the draftof the chimney fine.

The volume of the ventilating current may be regulated: as also thevolume of incoming-- fresh air, andthepassage of the fresh air throughits heating compartment may be re tarded'by interposed baflles or thecircuitous route within the compartment. r

The main volume of air recirculating from. the rooms to the furnacethrough the returnduct and past the heating surfaces, is expand ed andcirculates through the warm airducts to. the rooms, and: continues thatoperation over and over again increasing in temperature each time until:the required: heat in the rooms is maintained. A certain portion of thatrecirculating air is continuously withdrawn: for ventilation and isreplaced by fresh exteriorair. r

The advantage of thismethod of warm. air

circulation is that in addition toheat it pro vides fresh air andventilation to. the. rooms automatically without attentionor by thediscretion of the inhabitant.

I claim:-

1. A method/of circulating air through a furnace which consists inmaintaining a current of fresh exterior air separate fromthe current ofrecirculating air fromthe rooms of the building while the current offresh exterior air is being heated.

2. A method of circulating air through a furnace which consists inmaintaining a current of fresh exterior air separate from the current ofrecirculating air from the rooms ofthe building while the, current offresh exterior air is being heated, and then'mingling the two currentsof air before they pass to the rooms. I I

' 3;, method of circulating-fair throughfa furnace which consistsin'maintaining a cur rent of fresh exterior air separate from thecurrent of recirculating air from the rooms of the building while thecurrent of fresh exterior air is. being; l1eated:,.;and retarding it inits. passage while subjecting it to the heat.

4. A method of circulating. air through a furnace. which consists inmaintaining a cur 8 rent of fresh exterior air separate; front thecurrent of recirculating air from the 1, of the building while thecurrent of fresh exterior ainis being heated, at the same timewithdrawing a volume of air exteriorly from 9 the rooms. 7

5.; A method of circulating air through a furnace which consists. in.maintaining a cur-. rent of fresh exterior air separate from the currentof recirculating air: from the rooms of the building. while the currentof fresh exterior air isbeing heated, at the same time withdrawing avolume of air exteriorly from the rooms and regulating. the, volume. of"the air so withdrawn from the rooms.

from the rooms by means of the chimney draft.

7. A method of circulating air through a furnace consisting in maintaning acurrent of fresh exterior arr separate from the cur-I rent ofrecirculatingair from the rooms of thebuildingwhile the current of freshexterior air is being heatedgand retarding it in its passage while.subjecting it to the heat, then mingling the twocurrents of air beforethey pass to the-rooms, and at the same time withdrawing a volume ofaireXteriorly from. the rooms-and regulating the. volume of the air sowithdrawn from the rooms.

8. A method of circulating airthroug-h a furnace consisting inmaintaining a. current of fresh; exterior air separate from the current'of recirculating air. from the. rooms of the building while thecurrent of fresh exterior air isbeing heated, and their affording itpassage to the rooms without mingling it with the current ofrecirculating air within the furnace.

9. A method of circulating air through a then affording it passageto therooms withfurnace consisting in maintaining a current outvmingling itwith the current of recircu' of fresh exterior air separate from thecurlating air Within the furnace, and at the same 10 rent ofrecirculating air from the rooms of time Withdrawing a volume of airexteriorly 6 the building While the current of fresh ex from the rooms,and regulating the volume terior air is being heated and retarding it inof air so Withdrawn from the rooms. its passage while subjecting it tothe, heat, FREDERICK H. WOOD.

